Vinylidene chloride composition



Patented July 22, 194 1 UNITED STATES PATENT OFFICE VINYLIDENE CHLORIDE COMPOSITION Robert C. Reinhardt and John H. Reilly, Midland,

Mich., assignors to The Dow Chemical Company, Midland, Mich., a corporation of Michigan No Drawing. Original application November 16, 1938, Serial No. 240,661. Divided and this application November 28, 1940, Serial No. 367,577

I enic group.

3 Claims. (Cl. 260-32) i This invention relates to useful liquid dispersions or solutions of polymerized and copolymerized vinylidene chloride.

The problem of preparing solutions or dispersions (herein referred to simply'assolutions) of vinylidene chloride polymers and copolymers is rendered diflicult by the fact that such of the said polymeric bodies as dissolve readily in many of the common solvents are either too unstable or too low melting to be generally useful or desirable as ingredients of surface coating compositions, and the like. The converse is also true, i. e., the vinylidene chloride polymeric products which are sufllciently stable, and which have high enough softening points to be otherwise quers', films, threads, filaments, and powders of the said polymer or copolymer.

We have now found that the polymer of pure vinylidene chloride and the high softening copolymers wherein the copolymerized ingredient contains only one active ethylenic group, al-

acceptable as plastics, are insoluble in the usual solvents, such aschloroform, carbon bisulfide, ethylene bromide, or benzene, even at boiling temperature, and are only sparingly soluble in tetrachloroethane.

The polymer of pure vinylidene chloride, (monomer boils at 31.5-32 0.), which is insoluble in the above-named solvents, has a softening point at or above 170 C., is stable at tempera:- tures of about 210 C., or higher, and is substantially unchanged in composition when heated in though substantially insoluble in boiling chloroform, carbon bisulfide, ethylene bromide or benzene, may be made to form clear dispersions or solutions in certain selected solvents, which are useful in the preparation of lacquers, films and filaments, etc. The solvents which we have found satisfactory for this purpose are non-polar liquids boiling above 100 C., examples of which are the liquid polychlorinated aromatic hydrocarbons, the liquid (aliphatic, alicyclic, and alkylaryl)' ketones, and the (open-chain and cyclic) aliphatic ethers. Suitable polychlorinated hydrocarbons are: ortho-dichlorobenzene, trichlorobenzene, ethyl dichlorobenzene, and the like. The useful ketones boiling above 100 C. include methyl lsobutyl ketone, mesityl oxide, cyclohex anone, heptanone-2, acetophenone, etc. Ethers which are useful include dichloro-diethyl ether,

1.4-dioxane, 1.3-dioxane, and similar aliphatic ethers, boiling above 100 C.

a glass container at 180 C. The copolymers,

whose softening points are above 130 C., are prepared by polymerizing pure monomeric vinylidene chloride with a minor proportion of vinyl chloride, vinyl or other unsaturated esters of carboxylic acids, esters of acrylic or methacrylic acids, or styrene, and the like. These copolymers are also insoluble in'the solvents named above and are stable at temperatures at least 10 degrees above their respective softening points. The copolymers having the best properties for surface The solutions are prepared by heating the polymer or oopolymer with one or a mixture of the solvents of the previously named classes. Many of the solvents named, including orthodichlorobenzene and trichlorobenzene, retain the coating, film-, thread-, or filament-forming, and

similar purposes, are those wherein the copolymerized ingredient contains only one active ethylgroup is meant a carbon-to-carbon double bond,

which enters into the copolymeric structure under the polymerization conditions employed.

' In order to utilize these copolymers for the spepolymer of pure vinylidene chloride (boiling point 31.5-32 C.) and/or high-softening copolymers thereof with copolymerizable compounds By the expression active ethylenic polymer in clear solution only at temperatures above 140 C., below which temperature the composition becomes a gel. Hence, when the boiling point of the solvent employed permits of such temperatures, 140 C. is a good temperature at which to prepare .solutions. In all cases when the polymer or copolymer is dissolved or dispersed in a solvent of the class named, the resulting dispersion while hot has the appearance of a true solution. When cooled, however, it may in some cases take on the appearance of a colembodying the invention:

Example 1 The polymer of pure vinylidene chloride (20 I grams) is heated with trichlorobenzene v( cc.)

. polymer dissolves in the trichlorobenzene, and

containing only one active ethylenic group, which are suitable for use in the preparation of-lacto a temperature of about -170 C. The

remains in clear solution at temperatures above 143 C. Clear tough flexible films are formed by spreading the solution, at i50 (2., on a surface heated to 140 6., and drying the film.

Example 2 Twenty grams of a copolymer consisting of '70 per cent vinylidene chloride and 30 per cent vinyl acetate is dissolved in 80 grains of L-i-dioxane,

by warming.

Example 3 A 5 per cent solution in dioxane was prepared from a high-softening copolymer of 70 per cent Example 4 In a manner similar to Example 3, films were made from high-softening co-polymers of vinyliand the like in known manner.

dene chloride with ethyl acrylate, methyl methacrylate'a'nd styrene, respectively, employing cyclohexanone as the solvent.

The following table illustrates the preparation of lacquers from vinylidene chloride co-polymers. A number of co-polymers were dissolved to form 5 per cent solutions in dioxane. The dilution ratio of the dioxane solutions with various lacquer solvents and thinners was determined, and it' was ,polymer in solution,

The herein descri ed solutions of the pel 'cr of pure vinylidene chloride and. oi? e softening copolymers thereof are adapted to preparation or" surface-coating compositions and for making of foils, filaments, molding powders When the solution is to be employed at low temperature, such solvents as dioxane, cyclohexanone, acetophenone, heptanone-Z, methyl-isobutyl ketone, and the like, or mixtures thereof, are satisfactory. if the solutions are employed at high temperatures 2.5,f0l example, inthe casting of films, trichlcrobenzene and orthodichloro-benzene are preferred solvents.

This application is a division of our copend-. ing application-Serial No. 240,661, filed November 16, 1938, which, in turn, is a continuationin-part of our earlier application, Serial No. 151,182, filed June 30, 1937.

We claim:

1. A composition of matter comprising (1) apolymeric material which is insoluble in chloroform. carbon bisulfide, ethylene bromide, and benzene, said material having a softening point above 130 0., being thermo-stable at least to its softening point, and being selected from the group consisting of the polymer of pure vinylidene chloride and co-polymers thereof, containing only a minor proportion of a co-polymerized ingradient having only one active ethylenic group, completely dispersedto form a solution in (2) a liquid ketone having a boiling point above 100' C.

. 2. A composition of matter comprising. (1') a polymeric material which is insoluble in chloroform, carbon bisulfide, ethylene bromide, and benzene, said material having a softening point I above 130 C., being thermo-stable at least to Maximum Softening volume Diluent point of ratio, diluresin, C. ent: dloxone solution Carbon tetrachloride 132 2.0 'lolucno .l 132 3. 1 Naphtha 132 0. 7 Carbon tetrachloride 143 2. 3 Toluene 143 4. 1 Nap 143 0. 74 Carbon tetrachloride 154 l. 0 'lolucnc 154 1.3 Nnphtha 154 0. 0 Water 143 0.05 Alcohol, denatured, 05% 132 0. 3

Lacquer films deposited from such solutions have no visible crystal structure when examined under a microscope at 900 X magnification. The films organic solvents, or'by most non-polar solvents at ordinary temperatures.

' pletely dispersed to form a solution in its softening point, and being selected from the group consisting of the polymer of pure vinylidene chloride and co-polymers thereof containing only a minor proportion of a co-polymerized ingredient having only one active ethylenic group, com- (2) cyclohexanone.

3. A composition of matter comprising (1) a polymeric material which is insoluble in chloroform, carbon bisulfide, ethylene bromide, and benzene, said material having'a softening point above 0., being thermo-stable at least to its softening point, and being selected from the group consisting of the polymer of pure vinylidene chloride and co-polymers thereof containing only a minor proportion of a co -polymerized ingredient having only one active ethylenic group, completely dispersed to form a solution in (2) methyl-isobutyl-ketone.

ROBERT C. REINHARDT. JOHN H. -REI1LY. 

